The specified child already has a parent. You must call removeView() on the child's parent first.

[nnrohu]

I am trying to quit UnityView and go back to react-native screen.

[nnrohu]

I think the issue is here

 if (unityPlayer.getParent() != null) {
            ((ViewGroup) unityPlayer.getParent()).removeView(unityPlayer);
        }